A known process of this kind, the essential phases of which are carried out under high vacuum, includes mainly the passing of the "slice" into a deposition chamber in which by molecular projection, there is formed the active layer which, will then be cut up in order to form the semi-conductor components. Various operations, preparatory or complementary, precede or follow the operation of deposition, these various operations (heating, analysis, ionic bombardment, for example) being variable, depending upon the nature or the final destination of the resulting product.
At the present time, the known installations include an introduction chamber and an intermediate chamber upstream of the deposition chamber, each chamber being connected to vacuum equipment, with isolating valves between those chambers which are to be placed under different pressures. Hence the travel of a slice between its entering and its leaving the same chamber forms a journey outwards and return by the same route, so that the entire process must be completed before the next slice can be treated. The result is considerable dead time for the operation of the deposition chamber or of the auxiliary treatment apparatus, as well as vacuum losses which compel increased operation of the vacuum pumps and, in short, inefficient performance of the installation.
Attempts have already been made to replace slice-by-slice introduction into the installation by the introduction of "cassettes", i.e., of carriers upon which a number of slices may be arranged simultaneously, which are then manipulated together or one by one, depending upon whether the phases of the process are to be carried out as a whole or individually. The employment of carriers already enables the number of openings up to the free air of the introduction chamber, and consequently the employment of the vacuum pumps to be reduced but the complete treatment of all of the slices in a carrier must still take place before another carrier can be reloaded. Hence dead times persist for certain of the apparatus, which are not very compatible with the necessity of increasing the rhythm of production.